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1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/types.h>
3 #include <linux/sched.h>
4 #include <linux/module.h>
5 #include <linux/sunrpc/types.h>
6 #include <linux/sunrpc/xdr.h>
7 #include <linux/sunrpc/svcsock.h>
8 #include <linux/sunrpc/svcauth.h>
9 #include <linux/sunrpc/gss_api.h>
10 #include <linux/sunrpc/addr.h>
11 #include <linux/err.h>
12 #include <linux/seq_file.h>
13 #include <linux/hash.h>
14 #include <linux/string.h>
15 #include <linux/slab.h>
16 #include <net/sock.h>
17 #include <net/ipv6.h>
18 #include <linux/kernel.h>
19 #include <linux/user_namespace.h>
20 #define RPCDBG_FACILITY	RPCDBG_AUTH
21 
22 
23 #include "netns.h"
24 
25 /*
26  * AUTHUNIX and AUTHNULL credentials are both handled here.
27  * AUTHNULL is treated just like AUTHUNIX except that the uid/gid
28  * are always nobody (-2).  i.e. we do the same IP address checks for
29  * AUTHNULL as for AUTHUNIX, and that is done here.
30  */
31 
32 
33 struct unix_domain {
34 	struct auth_domain	h;
35 	/* other stuff later */
36 };
37 
38 extern struct auth_ops svcauth_null;
39 extern struct auth_ops svcauth_unix;
40 
svcauth_unix_domain_release_rcu(struct rcu_head * head)41 static void svcauth_unix_domain_release_rcu(struct rcu_head *head)
42 {
43 	struct auth_domain *dom = container_of(head, struct auth_domain, rcu_head);
44 	struct unix_domain *ud = container_of(dom, struct unix_domain, h);
45 
46 	kfree(dom->name);
47 	kfree(ud);
48 }
49 
svcauth_unix_domain_release(struct auth_domain * dom)50 static void svcauth_unix_domain_release(struct auth_domain *dom)
51 {
52 	call_rcu(&dom->rcu_head, svcauth_unix_domain_release_rcu);
53 }
54 
unix_domain_find(char * name)55 struct auth_domain *unix_domain_find(char *name)
56 {
57 	struct auth_domain *rv;
58 	struct unix_domain *new = NULL;
59 
60 	rv = auth_domain_find(name);
61 	while(1) {
62 		if (rv) {
63 			if (new && rv != &new->h)
64 				svcauth_unix_domain_release(&new->h);
65 
66 			if (rv->flavour != &svcauth_unix) {
67 				auth_domain_put(rv);
68 				return NULL;
69 			}
70 			return rv;
71 		}
72 
73 		new = kmalloc(sizeof(*new), GFP_KERNEL);
74 		if (new == NULL)
75 			return NULL;
76 		kref_init(&new->h.ref);
77 		new->h.name = kstrdup(name, GFP_KERNEL);
78 		if (new->h.name == NULL) {
79 			kfree(new);
80 			return NULL;
81 		}
82 		new->h.flavour = &svcauth_unix;
83 		rv = auth_domain_lookup(name, &new->h);
84 	}
85 }
86 EXPORT_SYMBOL_GPL(unix_domain_find);
87 
88 
89 /**************************************************
90  * cache for IP address to unix_domain
91  * as needed by AUTH_UNIX
92  */
93 #define	IP_HASHBITS	8
94 #define	IP_HASHMAX	(1<<IP_HASHBITS)
95 
96 struct ip_map {
97 	struct cache_head	h;
98 	char			m_class[8]; /* e.g. "nfsd" */
99 	struct in6_addr		m_addr;
100 	struct unix_domain	*m_client;
101 	struct rcu_head		m_rcu;
102 };
103 
ip_map_put(struct kref * kref)104 static void ip_map_put(struct kref *kref)
105 {
106 	struct cache_head *item = container_of(kref, struct cache_head, ref);
107 	struct ip_map *im = container_of(item, struct ip_map,h);
108 
109 	if (test_bit(CACHE_VALID, &item->flags) &&
110 	    !test_bit(CACHE_NEGATIVE, &item->flags))
111 		auth_domain_put(&im->m_client->h);
112 	kfree_rcu(im, m_rcu);
113 }
114 
hash_ip6(const struct in6_addr * ip)115 static inline int hash_ip6(const struct in6_addr *ip)
116 {
117 	return hash_32(ipv6_addr_hash(ip), IP_HASHBITS);
118 }
ip_map_match(struct cache_head * corig,struct cache_head * cnew)119 static int ip_map_match(struct cache_head *corig, struct cache_head *cnew)
120 {
121 	struct ip_map *orig = container_of(corig, struct ip_map, h);
122 	struct ip_map *new = container_of(cnew, struct ip_map, h);
123 	return strcmp(orig->m_class, new->m_class) == 0 &&
124 	       ipv6_addr_equal(&orig->m_addr, &new->m_addr);
125 }
ip_map_init(struct cache_head * cnew,struct cache_head * citem)126 static void ip_map_init(struct cache_head *cnew, struct cache_head *citem)
127 {
128 	struct ip_map *new = container_of(cnew, struct ip_map, h);
129 	struct ip_map *item = container_of(citem, struct ip_map, h);
130 
131 	strcpy(new->m_class, item->m_class);
132 	new->m_addr = item->m_addr;
133 }
update(struct cache_head * cnew,struct cache_head * citem)134 static void update(struct cache_head *cnew, struct cache_head *citem)
135 {
136 	struct ip_map *new = container_of(cnew, struct ip_map, h);
137 	struct ip_map *item = container_of(citem, struct ip_map, h);
138 
139 	kref_get(&item->m_client->h.ref);
140 	new->m_client = item->m_client;
141 }
ip_map_alloc(void)142 static struct cache_head *ip_map_alloc(void)
143 {
144 	struct ip_map *i = kmalloc(sizeof(*i), GFP_KERNEL);
145 	if (i)
146 		return &i->h;
147 	else
148 		return NULL;
149 }
150 
ip_map_request(struct cache_detail * cd,struct cache_head * h,char ** bpp,int * blen)151 static void ip_map_request(struct cache_detail *cd,
152 				  struct cache_head *h,
153 				  char **bpp, int *blen)
154 {
155 	char text_addr[40];
156 	struct ip_map *im = container_of(h, struct ip_map, h);
157 
158 	if (ipv6_addr_v4mapped(&(im->m_addr))) {
159 		snprintf(text_addr, 20, "%pI4", &im->m_addr.s6_addr32[3]);
160 	} else {
161 		snprintf(text_addr, 40, "%pI6", &im->m_addr);
162 	}
163 	qword_add(bpp, blen, im->m_class);
164 	qword_add(bpp, blen, text_addr);
165 	(*bpp)[-1] = '\n';
166 }
167 
168 static struct ip_map *__ip_map_lookup(struct cache_detail *cd, char *class, struct in6_addr *addr);
169 static int __ip_map_update(struct cache_detail *cd, struct ip_map *ipm, struct unix_domain *udom, time_t expiry);
170 
ip_map_parse(struct cache_detail * cd,char * mesg,int mlen)171 static int ip_map_parse(struct cache_detail *cd,
172 			  char *mesg, int mlen)
173 {
174 	/* class ipaddress [domainname] */
175 	/* should be safe just to use the start of the input buffer
176 	 * for scratch: */
177 	char *buf = mesg;
178 	int len;
179 	char class[8];
180 	union {
181 		struct sockaddr		sa;
182 		struct sockaddr_in	s4;
183 		struct sockaddr_in6	s6;
184 	} address;
185 	struct sockaddr_in6 sin6;
186 	int err;
187 
188 	struct ip_map *ipmp;
189 	struct auth_domain *dom;
190 	time_t expiry;
191 
192 	if (mesg[mlen-1] != '\n')
193 		return -EINVAL;
194 	mesg[mlen-1] = 0;
195 
196 	/* class */
197 	len = qword_get(&mesg, class, sizeof(class));
198 	if (len <= 0) return -EINVAL;
199 
200 	/* ip address */
201 	len = qword_get(&mesg, buf, mlen);
202 	if (len <= 0) return -EINVAL;
203 
204 	if (rpc_pton(cd->net, buf, len, &address.sa, sizeof(address)) == 0)
205 		return -EINVAL;
206 	switch (address.sa.sa_family) {
207 	case AF_INET:
208 		/* Form a mapped IPv4 address in sin6 */
209 		sin6.sin6_family = AF_INET6;
210 		ipv6_addr_set_v4mapped(address.s4.sin_addr.s_addr,
211 				&sin6.sin6_addr);
212 		break;
213 #if IS_ENABLED(CONFIG_IPV6)
214 	case AF_INET6:
215 		memcpy(&sin6, &address.s6, sizeof(sin6));
216 		break;
217 #endif
218 	default:
219 		return -EINVAL;
220 	}
221 
222 	expiry = get_expiry(&mesg);
223 	if (expiry ==0)
224 		return -EINVAL;
225 
226 	/* domainname, or empty for NEGATIVE */
227 	len = qword_get(&mesg, buf, mlen);
228 	if (len < 0) return -EINVAL;
229 
230 	if (len) {
231 		dom = unix_domain_find(buf);
232 		if (dom == NULL)
233 			return -ENOENT;
234 	} else
235 		dom = NULL;
236 
237 	/* IPv6 scope IDs are ignored for now */
238 	ipmp = __ip_map_lookup(cd, class, &sin6.sin6_addr);
239 	if (ipmp) {
240 		err = __ip_map_update(cd, ipmp,
241 			     container_of(dom, struct unix_domain, h),
242 			     expiry);
243 	} else
244 		err = -ENOMEM;
245 
246 	if (dom)
247 		auth_domain_put(dom);
248 
249 	cache_flush();
250 	return err;
251 }
252 
ip_map_show(struct seq_file * m,struct cache_detail * cd,struct cache_head * h)253 static int ip_map_show(struct seq_file *m,
254 		       struct cache_detail *cd,
255 		       struct cache_head *h)
256 {
257 	struct ip_map *im;
258 	struct in6_addr addr;
259 	char *dom = "-no-domain-";
260 
261 	if (h == NULL) {
262 		seq_puts(m, "#class IP domain\n");
263 		return 0;
264 	}
265 	im = container_of(h, struct ip_map, h);
266 	/* class addr domain */
267 	addr = im->m_addr;
268 
269 	if (test_bit(CACHE_VALID, &h->flags) &&
270 	    !test_bit(CACHE_NEGATIVE, &h->flags))
271 		dom = im->m_client->h.name;
272 
273 	if (ipv6_addr_v4mapped(&addr)) {
274 		seq_printf(m, "%s %pI4 %s\n",
275 			im->m_class, &addr.s6_addr32[3], dom);
276 	} else {
277 		seq_printf(m, "%s %pI6 %s\n", im->m_class, &addr, dom);
278 	}
279 	return 0;
280 }
281 
282 
__ip_map_lookup(struct cache_detail * cd,char * class,struct in6_addr * addr)283 static struct ip_map *__ip_map_lookup(struct cache_detail *cd, char *class,
284 		struct in6_addr *addr)
285 {
286 	struct ip_map ip;
287 	struct cache_head *ch;
288 
289 	strcpy(ip.m_class, class);
290 	ip.m_addr = *addr;
291 	ch = sunrpc_cache_lookup_rcu(cd, &ip.h,
292 				     hash_str(class, IP_HASHBITS) ^
293 				     hash_ip6(addr));
294 
295 	if (ch)
296 		return container_of(ch, struct ip_map, h);
297 	else
298 		return NULL;
299 }
300 
ip_map_lookup(struct net * net,char * class,struct in6_addr * addr)301 static inline struct ip_map *ip_map_lookup(struct net *net, char *class,
302 		struct in6_addr *addr)
303 {
304 	struct sunrpc_net *sn;
305 
306 	sn = net_generic(net, sunrpc_net_id);
307 	return __ip_map_lookup(sn->ip_map_cache, class, addr);
308 }
309 
__ip_map_update(struct cache_detail * cd,struct ip_map * ipm,struct unix_domain * udom,time_t expiry)310 static int __ip_map_update(struct cache_detail *cd, struct ip_map *ipm,
311 		struct unix_domain *udom, time_t expiry)
312 {
313 	struct ip_map ip;
314 	struct cache_head *ch;
315 
316 	ip.m_client = udom;
317 	ip.h.flags = 0;
318 	if (!udom)
319 		set_bit(CACHE_NEGATIVE, &ip.h.flags);
320 	ip.h.expiry_time = expiry;
321 	ch = sunrpc_cache_update(cd, &ip.h, &ipm->h,
322 				 hash_str(ipm->m_class, IP_HASHBITS) ^
323 				 hash_ip6(&ipm->m_addr));
324 	if (!ch)
325 		return -ENOMEM;
326 	cache_put(ch, cd);
327 	return 0;
328 }
329 
ip_map_update(struct net * net,struct ip_map * ipm,struct unix_domain * udom,time_t expiry)330 static inline int ip_map_update(struct net *net, struct ip_map *ipm,
331 		struct unix_domain *udom, time_t expiry)
332 {
333 	struct sunrpc_net *sn;
334 
335 	sn = net_generic(net, sunrpc_net_id);
336 	return __ip_map_update(sn->ip_map_cache, ipm, udom, expiry);
337 }
338 
svcauth_unix_purge(struct net * net)339 void svcauth_unix_purge(struct net *net)
340 {
341 	struct sunrpc_net *sn;
342 
343 	sn = net_generic(net, sunrpc_net_id);
344 	cache_purge(sn->ip_map_cache);
345 }
346 EXPORT_SYMBOL_GPL(svcauth_unix_purge);
347 
348 static inline struct ip_map *
ip_map_cached_get(struct svc_xprt * xprt)349 ip_map_cached_get(struct svc_xprt *xprt)
350 {
351 	struct ip_map *ipm = NULL;
352 	struct sunrpc_net *sn;
353 
354 	if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags)) {
355 		spin_lock(&xprt->xpt_lock);
356 		ipm = xprt->xpt_auth_cache;
357 		if (ipm != NULL) {
358 			sn = net_generic(xprt->xpt_net, sunrpc_net_id);
359 			if (cache_is_expired(sn->ip_map_cache, &ipm->h)) {
360 				/*
361 				 * The entry has been invalidated since it was
362 				 * remembered, e.g. by a second mount from the
363 				 * same IP address.
364 				 */
365 				xprt->xpt_auth_cache = NULL;
366 				spin_unlock(&xprt->xpt_lock);
367 				cache_put(&ipm->h, sn->ip_map_cache);
368 				return NULL;
369 			}
370 			cache_get(&ipm->h);
371 		}
372 		spin_unlock(&xprt->xpt_lock);
373 	}
374 	return ipm;
375 }
376 
377 static inline void
ip_map_cached_put(struct svc_xprt * xprt,struct ip_map * ipm)378 ip_map_cached_put(struct svc_xprt *xprt, struct ip_map *ipm)
379 {
380 	if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags)) {
381 		spin_lock(&xprt->xpt_lock);
382 		if (xprt->xpt_auth_cache == NULL) {
383 			/* newly cached, keep the reference */
384 			xprt->xpt_auth_cache = ipm;
385 			ipm = NULL;
386 		}
387 		spin_unlock(&xprt->xpt_lock);
388 	}
389 	if (ipm) {
390 		struct sunrpc_net *sn;
391 
392 		sn = net_generic(xprt->xpt_net, sunrpc_net_id);
393 		cache_put(&ipm->h, sn->ip_map_cache);
394 	}
395 }
396 
397 void
svcauth_unix_info_release(struct svc_xprt * xpt)398 svcauth_unix_info_release(struct svc_xprt *xpt)
399 {
400 	struct ip_map *ipm;
401 
402 	ipm = xpt->xpt_auth_cache;
403 	if (ipm != NULL) {
404 		struct sunrpc_net *sn;
405 
406 		sn = net_generic(xpt->xpt_net, sunrpc_net_id);
407 		cache_put(&ipm->h, sn->ip_map_cache);
408 	}
409 }
410 
411 /****************************************************************************
412  * auth.unix.gid cache
413  * simple cache to map a UID to a list of GIDs
414  * because AUTH_UNIX aka AUTH_SYS has a max of UNX_NGROUPS
415  */
416 #define	GID_HASHBITS	8
417 #define	GID_HASHMAX	(1<<GID_HASHBITS)
418 
419 struct unix_gid {
420 	struct cache_head	h;
421 	kuid_t			uid;
422 	struct group_info	*gi;
423 	struct rcu_head		rcu;
424 };
425 
unix_gid_hash(kuid_t uid)426 static int unix_gid_hash(kuid_t uid)
427 {
428 	return hash_long(from_kuid(&init_user_ns, uid), GID_HASHBITS);
429 }
430 
unix_gid_free(struct rcu_head * rcu)431 static void unix_gid_free(struct rcu_head *rcu)
432 {
433 	struct unix_gid *ug = container_of(rcu, struct unix_gid, rcu);
434 	struct cache_head *item = &ug->h;
435 
436 	if (test_bit(CACHE_VALID, &item->flags) &&
437 	    !test_bit(CACHE_NEGATIVE, &item->flags))
438 		put_group_info(ug->gi);
439 	kfree(ug);
440 }
441 
unix_gid_put(struct kref * kref)442 static void unix_gid_put(struct kref *kref)
443 {
444 	struct cache_head *item = container_of(kref, struct cache_head, ref);
445 	struct unix_gid *ug = container_of(item, struct unix_gid, h);
446 
447 	call_rcu(&ug->rcu, unix_gid_free);
448 }
449 
unix_gid_match(struct cache_head * corig,struct cache_head * cnew)450 static int unix_gid_match(struct cache_head *corig, struct cache_head *cnew)
451 {
452 	struct unix_gid *orig = container_of(corig, struct unix_gid, h);
453 	struct unix_gid *new = container_of(cnew, struct unix_gid, h);
454 	return uid_eq(orig->uid, new->uid);
455 }
unix_gid_init(struct cache_head * cnew,struct cache_head * citem)456 static void unix_gid_init(struct cache_head *cnew, struct cache_head *citem)
457 {
458 	struct unix_gid *new = container_of(cnew, struct unix_gid, h);
459 	struct unix_gid *item = container_of(citem, struct unix_gid, h);
460 	new->uid = item->uid;
461 }
unix_gid_update(struct cache_head * cnew,struct cache_head * citem)462 static void unix_gid_update(struct cache_head *cnew, struct cache_head *citem)
463 {
464 	struct unix_gid *new = container_of(cnew, struct unix_gid, h);
465 	struct unix_gid *item = container_of(citem, struct unix_gid, h);
466 
467 	get_group_info(item->gi);
468 	new->gi = item->gi;
469 }
unix_gid_alloc(void)470 static struct cache_head *unix_gid_alloc(void)
471 {
472 	struct unix_gid *g = kmalloc(sizeof(*g), GFP_KERNEL);
473 	if (g)
474 		return &g->h;
475 	else
476 		return NULL;
477 }
478 
unix_gid_request(struct cache_detail * cd,struct cache_head * h,char ** bpp,int * blen)479 static void unix_gid_request(struct cache_detail *cd,
480 			     struct cache_head *h,
481 			     char **bpp, int *blen)
482 {
483 	char tuid[20];
484 	struct unix_gid *ug = container_of(h, struct unix_gid, h);
485 
486 	snprintf(tuid, 20, "%u", from_kuid(&init_user_ns, ug->uid));
487 	qword_add(bpp, blen, tuid);
488 	(*bpp)[-1] = '\n';
489 }
490 
491 static struct unix_gid *unix_gid_lookup(struct cache_detail *cd, kuid_t uid);
492 
unix_gid_parse(struct cache_detail * cd,char * mesg,int mlen)493 static int unix_gid_parse(struct cache_detail *cd,
494 			char *mesg, int mlen)
495 {
496 	/* uid expiry Ngid gid0 gid1 ... gidN-1 */
497 	int id;
498 	kuid_t uid;
499 	int gids;
500 	int rv;
501 	int i;
502 	int err;
503 	time_t expiry;
504 	struct unix_gid ug, *ugp;
505 
506 	if (mesg[mlen - 1] != '\n')
507 		return -EINVAL;
508 	mesg[mlen-1] = 0;
509 
510 	rv = get_int(&mesg, &id);
511 	if (rv)
512 		return -EINVAL;
513 	uid = make_kuid(current_user_ns(), id);
514 	ug.uid = uid;
515 
516 	expiry = get_expiry(&mesg);
517 	if (expiry == 0)
518 		return -EINVAL;
519 
520 	rv = get_int(&mesg, &gids);
521 	if (rv || gids < 0 || gids > 8192)
522 		return -EINVAL;
523 
524 	ug.gi = groups_alloc(gids);
525 	if (!ug.gi)
526 		return -ENOMEM;
527 
528 	for (i = 0 ; i < gids ; i++) {
529 		int gid;
530 		kgid_t kgid;
531 		rv = get_int(&mesg, &gid);
532 		err = -EINVAL;
533 		if (rv)
534 			goto out;
535 		kgid = make_kgid(current_user_ns(), gid);
536 		if (!gid_valid(kgid))
537 			goto out;
538 		ug.gi->gid[i] = kgid;
539 	}
540 
541 	groups_sort(ug.gi);
542 	ugp = unix_gid_lookup(cd, uid);
543 	if (ugp) {
544 		struct cache_head *ch;
545 		ug.h.flags = 0;
546 		ug.h.expiry_time = expiry;
547 		ch = sunrpc_cache_update(cd,
548 					 &ug.h, &ugp->h,
549 					 unix_gid_hash(uid));
550 		if (!ch)
551 			err = -ENOMEM;
552 		else {
553 			err = 0;
554 			cache_put(ch, cd);
555 		}
556 	} else
557 		err = -ENOMEM;
558  out:
559 	if (ug.gi)
560 		put_group_info(ug.gi);
561 	return err;
562 }
563 
unix_gid_show(struct seq_file * m,struct cache_detail * cd,struct cache_head * h)564 static int unix_gid_show(struct seq_file *m,
565 			 struct cache_detail *cd,
566 			 struct cache_head *h)
567 {
568 	struct user_namespace *user_ns = m->file->f_cred->user_ns;
569 	struct unix_gid *ug;
570 	int i;
571 	int glen;
572 
573 	if (h == NULL) {
574 		seq_puts(m, "#uid cnt: gids...\n");
575 		return 0;
576 	}
577 	ug = container_of(h, struct unix_gid, h);
578 	if (test_bit(CACHE_VALID, &h->flags) &&
579 	    !test_bit(CACHE_NEGATIVE, &h->flags))
580 		glen = ug->gi->ngroups;
581 	else
582 		glen = 0;
583 
584 	seq_printf(m, "%u %d:", from_kuid_munged(user_ns, ug->uid), glen);
585 	for (i = 0; i < glen; i++)
586 		seq_printf(m, " %d", from_kgid_munged(user_ns, ug->gi->gid[i]));
587 	seq_printf(m, "\n");
588 	return 0;
589 }
590 
591 static const struct cache_detail unix_gid_cache_template = {
592 	.owner		= THIS_MODULE,
593 	.hash_size	= GID_HASHMAX,
594 	.name		= "auth.unix.gid",
595 	.cache_put	= unix_gid_put,
596 	.cache_request	= unix_gid_request,
597 	.cache_parse	= unix_gid_parse,
598 	.cache_show	= unix_gid_show,
599 	.match		= unix_gid_match,
600 	.init		= unix_gid_init,
601 	.update		= unix_gid_update,
602 	.alloc		= unix_gid_alloc,
603 };
604 
unix_gid_cache_create(struct net * net)605 int unix_gid_cache_create(struct net *net)
606 {
607 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
608 	struct cache_detail *cd;
609 	int err;
610 
611 	cd = cache_create_net(&unix_gid_cache_template, net);
612 	if (IS_ERR(cd))
613 		return PTR_ERR(cd);
614 	err = cache_register_net(cd, net);
615 	if (err) {
616 		cache_destroy_net(cd, net);
617 		return err;
618 	}
619 	sn->unix_gid_cache = cd;
620 	return 0;
621 }
622 
unix_gid_cache_destroy(struct net * net)623 void unix_gid_cache_destroy(struct net *net)
624 {
625 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
626 	struct cache_detail *cd = sn->unix_gid_cache;
627 
628 	sn->unix_gid_cache = NULL;
629 	cache_purge(cd);
630 	cache_unregister_net(cd, net);
631 	cache_destroy_net(cd, net);
632 }
633 
unix_gid_lookup(struct cache_detail * cd,kuid_t uid)634 static struct unix_gid *unix_gid_lookup(struct cache_detail *cd, kuid_t uid)
635 {
636 	struct unix_gid ug;
637 	struct cache_head *ch;
638 
639 	ug.uid = uid;
640 	ch = sunrpc_cache_lookup_rcu(cd, &ug.h, unix_gid_hash(uid));
641 	if (ch)
642 		return container_of(ch, struct unix_gid, h);
643 	else
644 		return NULL;
645 }
646 
unix_gid_find(kuid_t uid,struct svc_rqst * rqstp)647 static struct group_info *unix_gid_find(kuid_t uid, struct svc_rqst *rqstp)
648 {
649 	struct unix_gid *ug;
650 	struct group_info *gi;
651 	int ret;
652 	struct sunrpc_net *sn = net_generic(rqstp->rq_xprt->xpt_net,
653 					    sunrpc_net_id);
654 
655 	ug = unix_gid_lookup(sn->unix_gid_cache, uid);
656 	if (!ug)
657 		return ERR_PTR(-EAGAIN);
658 	ret = cache_check(sn->unix_gid_cache, &ug->h, &rqstp->rq_chandle);
659 	switch (ret) {
660 	case -ENOENT:
661 		return ERR_PTR(-ENOENT);
662 	case -ETIMEDOUT:
663 		return ERR_PTR(-ESHUTDOWN);
664 	case 0:
665 		gi = get_group_info(ug->gi);
666 		cache_put(&ug->h, sn->unix_gid_cache);
667 		return gi;
668 	default:
669 		return ERR_PTR(-EAGAIN);
670 	}
671 }
672 
673 int
svcauth_unix_set_client(struct svc_rqst * rqstp)674 svcauth_unix_set_client(struct svc_rqst *rqstp)
675 {
676 	struct sockaddr_in *sin;
677 	struct sockaddr_in6 *sin6, sin6_storage;
678 	struct ip_map *ipm;
679 	struct group_info *gi;
680 	struct svc_cred *cred = &rqstp->rq_cred;
681 	struct svc_xprt *xprt = rqstp->rq_xprt;
682 	struct net *net = xprt->xpt_net;
683 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
684 
685 	switch (rqstp->rq_addr.ss_family) {
686 	case AF_INET:
687 		sin = svc_addr_in(rqstp);
688 		sin6 = &sin6_storage;
689 		ipv6_addr_set_v4mapped(sin->sin_addr.s_addr, &sin6->sin6_addr);
690 		break;
691 	case AF_INET6:
692 		sin6 = svc_addr_in6(rqstp);
693 		break;
694 	default:
695 		BUG();
696 	}
697 
698 	rqstp->rq_client = NULL;
699 	if (rqstp->rq_proc == 0)
700 		return SVC_OK;
701 
702 	ipm = ip_map_cached_get(xprt);
703 	if (ipm == NULL)
704 		ipm = __ip_map_lookup(sn->ip_map_cache, rqstp->rq_server->sv_program->pg_class,
705 				    &sin6->sin6_addr);
706 
707 	if (ipm == NULL)
708 		return SVC_DENIED;
709 
710 	switch (cache_check(sn->ip_map_cache, &ipm->h, &rqstp->rq_chandle)) {
711 		default:
712 			BUG();
713 		case -ETIMEDOUT:
714 			return SVC_CLOSE;
715 		case -EAGAIN:
716 			return SVC_DROP;
717 		case -ENOENT:
718 			return SVC_DENIED;
719 		case 0:
720 			rqstp->rq_client = &ipm->m_client->h;
721 			kref_get(&rqstp->rq_client->ref);
722 			ip_map_cached_put(xprt, ipm);
723 			break;
724 	}
725 
726 	gi = unix_gid_find(cred->cr_uid, rqstp);
727 	switch (PTR_ERR(gi)) {
728 	case -EAGAIN:
729 		return SVC_DROP;
730 	case -ESHUTDOWN:
731 		return SVC_CLOSE;
732 	case -ENOENT:
733 		break;
734 	default:
735 		put_group_info(cred->cr_group_info);
736 		cred->cr_group_info = gi;
737 	}
738 	return SVC_OK;
739 }
740 
741 EXPORT_SYMBOL_GPL(svcauth_unix_set_client);
742 
743 static int
svcauth_null_accept(struct svc_rqst * rqstp,__be32 * authp)744 svcauth_null_accept(struct svc_rqst *rqstp, __be32 *authp)
745 {
746 	struct kvec	*argv = &rqstp->rq_arg.head[0];
747 	struct kvec	*resv = &rqstp->rq_res.head[0];
748 	struct svc_cred	*cred = &rqstp->rq_cred;
749 
750 	if (argv->iov_len < 3*4)
751 		return SVC_GARBAGE;
752 
753 	if (svc_getu32(argv) != 0) {
754 		dprintk("svc: bad null cred\n");
755 		*authp = rpc_autherr_badcred;
756 		return SVC_DENIED;
757 	}
758 	if (svc_getu32(argv) != htonl(RPC_AUTH_NULL) || svc_getu32(argv) != 0) {
759 		dprintk("svc: bad null verf\n");
760 		*authp = rpc_autherr_badverf;
761 		return SVC_DENIED;
762 	}
763 
764 	/* Signal that mapping to nobody uid/gid is required */
765 	cred->cr_uid = INVALID_UID;
766 	cred->cr_gid = INVALID_GID;
767 	cred->cr_group_info = groups_alloc(0);
768 	if (cred->cr_group_info == NULL)
769 		return SVC_CLOSE; /* kmalloc failure - client must retry */
770 
771 	/* Put NULL verifier */
772 	svc_putnl(resv, RPC_AUTH_NULL);
773 	svc_putnl(resv, 0);
774 
775 	rqstp->rq_cred.cr_flavor = RPC_AUTH_NULL;
776 	return SVC_OK;
777 }
778 
779 static int
svcauth_null_release(struct svc_rqst * rqstp)780 svcauth_null_release(struct svc_rqst *rqstp)
781 {
782 	if (rqstp->rq_client)
783 		auth_domain_put(rqstp->rq_client);
784 	rqstp->rq_client = NULL;
785 	if (rqstp->rq_cred.cr_group_info)
786 		put_group_info(rqstp->rq_cred.cr_group_info);
787 	rqstp->rq_cred.cr_group_info = NULL;
788 
789 	return 0; /* don't drop */
790 }
791 
792 
793 struct auth_ops svcauth_null = {
794 	.name		= "null",
795 	.owner		= THIS_MODULE,
796 	.flavour	= RPC_AUTH_NULL,
797 	.accept 	= svcauth_null_accept,
798 	.release	= svcauth_null_release,
799 	.set_client	= svcauth_unix_set_client,
800 };
801 
802 
803 static int
svcauth_unix_accept(struct svc_rqst * rqstp,__be32 * authp)804 svcauth_unix_accept(struct svc_rqst *rqstp, __be32 *authp)
805 {
806 	struct kvec	*argv = &rqstp->rq_arg.head[0];
807 	struct kvec	*resv = &rqstp->rq_res.head[0];
808 	struct svc_cred	*cred = &rqstp->rq_cred;
809 	struct user_namespace *userns;
810 	u32		slen, i;
811 	int		len   = argv->iov_len;
812 
813 	if ((len -= 3*4) < 0)
814 		return SVC_GARBAGE;
815 
816 	svc_getu32(argv);			/* length */
817 	svc_getu32(argv);			/* time stamp */
818 	slen = XDR_QUADLEN(svc_getnl(argv));	/* machname length */
819 	if (slen > 64 || (len -= (slen + 3)*4) < 0)
820 		goto badcred;
821 	argv->iov_base = (void*)((__be32*)argv->iov_base + slen);	/* skip machname */
822 	argv->iov_len -= slen*4;
823 	/*
824 	 * Note: we skip uid_valid()/gid_valid() checks here for
825 	 * backwards compatibility with clients that use -1 id's.
826 	 * Instead, -1 uid or gid is later mapped to the
827 	 * (export-specific) anonymous id by nfsd_setuser.
828 	 * Supplementary gid's will be left alone.
829 	 */
830 	userns = (rqstp->rq_xprt && rqstp->rq_xprt->xpt_cred) ?
831 		rqstp->rq_xprt->xpt_cred->user_ns : &init_user_ns;
832 	cred->cr_uid = make_kuid(userns, svc_getnl(argv)); /* uid */
833 	cred->cr_gid = make_kgid(userns, svc_getnl(argv)); /* gid */
834 	slen = svc_getnl(argv);			/* gids length */
835 	if (slen > UNX_NGROUPS || (len -= (slen + 2)*4) < 0)
836 		goto badcred;
837 	cred->cr_group_info = groups_alloc(slen);
838 	if (cred->cr_group_info == NULL)
839 		return SVC_CLOSE;
840 	for (i = 0; i < slen; i++) {
841 		kgid_t kgid = make_kgid(userns, svc_getnl(argv));
842 		cred->cr_group_info->gid[i] = kgid;
843 	}
844 	groups_sort(cred->cr_group_info);
845 	if (svc_getu32(argv) != htonl(RPC_AUTH_NULL) || svc_getu32(argv) != 0) {
846 		*authp = rpc_autherr_badverf;
847 		return SVC_DENIED;
848 	}
849 
850 	/* Put NULL verifier */
851 	svc_putnl(resv, RPC_AUTH_NULL);
852 	svc_putnl(resv, 0);
853 
854 	rqstp->rq_cred.cr_flavor = RPC_AUTH_UNIX;
855 	return SVC_OK;
856 
857 badcred:
858 	*authp = rpc_autherr_badcred;
859 	return SVC_DENIED;
860 }
861 
862 static int
svcauth_unix_release(struct svc_rqst * rqstp)863 svcauth_unix_release(struct svc_rqst *rqstp)
864 {
865 	/* Verifier (such as it is) is already in place.
866 	 */
867 	if (rqstp->rq_client)
868 		auth_domain_put(rqstp->rq_client);
869 	rqstp->rq_client = NULL;
870 	if (rqstp->rq_cred.cr_group_info)
871 		put_group_info(rqstp->rq_cred.cr_group_info);
872 	rqstp->rq_cred.cr_group_info = NULL;
873 
874 	return 0;
875 }
876 
877 
878 struct auth_ops svcauth_unix = {
879 	.name		= "unix",
880 	.owner		= THIS_MODULE,
881 	.flavour	= RPC_AUTH_UNIX,
882 	.accept 	= svcauth_unix_accept,
883 	.release	= svcauth_unix_release,
884 	.domain_release	= svcauth_unix_domain_release,
885 	.set_client	= svcauth_unix_set_client,
886 };
887 
888 static const struct cache_detail ip_map_cache_template = {
889 	.owner		= THIS_MODULE,
890 	.hash_size	= IP_HASHMAX,
891 	.name		= "auth.unix.ip",
892 	.cache_put	= ip_map_put,
893 	.cache_request	= ip_map_request,
894 	.cache_parse	= ip_map_parse,
895 	.cache_show	= ip_map_show,
896 	.match		= ip_map_match,
897 	.init		= ip_map_init,
898 	.update		= update,
899 	.alloc		= ip_map_alloc,
900 };
901 
ip_map_cache_create(struct net * net)902 int ip_map_cache_create(struct net *net)
903 {
904 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
905 	struct cache_detail *cd;
906 	int err;
907 
908 	cd = cache_create_net(&ip_map_cache_template, net);
909 	if (IS_ERR(cd))
910 		return PTR_ERR(cd);
911 	err = cache_register_net(cd, net);
912 	if (err) {
913 		cache_destroy_net(cd, net);
914 		return err;
915 	}
916 	sn->ip_map_cache = cd;
917 	return 0;
918 }
919 
ip_map_cache_destroy(struct net * net)920 void ip_map_cache_destroy(struct net *net)
921 {
922 	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
923 	struct cache_detail *cd = sn->ip_map_cache;
924 
925 	sn->ip_map_cache = NULL;
926 	cache_purge(cd);
927 	cache_unregister_net(cd, net);
928 	cache_destroy_net(cd, net);
929 }
930